Arc-lamp.



J. L. DINSMOOR.

ARC LAMP.

APPLICATION FILED APR.24. 1913.

1 38,277. Patented Aug. 28, 1917.

iTN ES:

INVENTOR 4' 7 9 fl f fl z mi/r/b/ I {Q5 H3 BY J W ATTORNEY UNITED STATESPATENT OFFICE.

JOHN L. DINSMOOR, OF BROOKLYN, NEW YORK, ASSIONOB TO WESTINGHOUSENLECTRIO AN'D MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

ARC-LAMP.

Specification of Letters Patent.

Patented Aug". 28, 1917.

Application filed April 24, 1913. Serial No. 763,283.

To all whom it may concern:

Be it known that I, JOHN L. DiNsMooR, a citizen of the United States,and a resident of Brooklyn, in the county of Kings and State of NewYork, have invented a new and useful I mprovcmcnt in Arc-Lamps, of whichthe following is a specification.

My invention relates to electric arc lamps, and it has particularreference to means for substantially eliminating or neutralizing thedisturbing magnetic fields in the vicinity of the arcs.

Because an electric arc is a gaseous conductor of electric current, itpossesses qualities that detract from its stability and cause aflickering of the light emitted therefrom. Some of the disturbingfactors upon arc stability are heat radiation, expansion and diffusionof the gaseous medium of the arc, forces resulting from air currents,and magnetic fields existing in the vicinity of the arc. In modern typesof arc lamps, the magnetic fields existing in the vicinity of the areare the disturbing factors which most affect its stability. Inasmuch asan unsymmetrical magnetic field produces perceptible changes in theshape and position of the arc, it is important that the disturbingforces resulting from such a magnetic field be minimized to asubstantially low value.

An are burning under the influence of adjacent and unsymmetricallydisposed magnetic fields will be distorted and eventually will crawl upthe sides of the upper electrode and cause uneven burning of the arcingend of the electrode. This results ina further distortion of the shapeof the normal are followed by an actual change in its position andultimately in an elongation which terminates often in the rupture of theare.

One object of my invention is to provide means, in an electric arc lamp,for substantially eliminating or minimizing the disturbing magneticforces which ma arise from the magnetic fields adjacent to t e arc.

Another object of my invention is to pro vide means in an electric arclamp, for in suring stability of the arc and thereby preventin materialflickering of the light which is emitted'from the arc.

A further object of my invention is {to provide means, in an electricarc lamp that will cause the surfaces of the opposing ends the are.

of the electrodes to burn evenly during the consumption of theelectrodes.

For a better understanding of thenature of m mvention, reference may behad to the ollowing description and the neon! panying drawing in whichFigure l is a side view, partially in section, of a ortion of an arclamp equipped with a evice embodying one form of my invention; Fig. 2 1sa front view of my device, showing its position relative to theoperating position of the electrodes of the lamp, and Fig. 3 is a frontview of my device.

Referring to the drawings, the are 1. be tween theopposing ends of anupper-electrode 2 and a lower electrode 3, is incloserl by a globe (notshown) which excludes ill air currents from the immediate vicinity ofThe electric current of the are 1 1s conducted by a supporting rod 4which passes slldingly through a sleeveo, a holder 6, the lowerelectrode 3 and the upper electrode 2. As the current flows along therod 4 and through the other conductors embodied in the lamp, itgenerates a magnetic field unsymmetrically disposed around the are 1which unbalances the arc and decreases its stability. A device 7 shownin Fig. 3 and constructed in accordance with my invention, is placedupon the tapered sleeve 5 in the osition shown in the drawings. Thedevice, 7 which constitutes a magnet having a north pole and a southpole is made of paramagnetic material, preferably sheet steel of highpermeability. Its shape. conforms substantially to at of a strip ofmaterial of definite width being wound upon a section of a helix andprovided with a slot 8 which extends parallel to the direction of theaxis of the helix. As a result, the device 7 may be considered as madeof a strip of metal at the ends of which magnetic poles may be formedwhen subjected to a magnetizing force. When current flows along the rod4, this magnetizing force is generated thereby forming a pair of polesat the opposing ends of the strip of metal which are spaced from eachother by the slot 8.

Referring to Figs. 1 and 2, the magnet 7 is shown positioned upon thesleeve 5 with the slot 8 adjacent to the side of the sleeve 5 which isthe more remote from the are 1. In

fir

order tq S QCl e vcriy b en finial results u on the are resulting\I'Qll] tie magnet 7, the slot 8 should be disposed opposite to thespace extending between the opposing ends of: the electrodesflland 3when inftheiri openating position. By reason ofthe'magnetic fieldgenerated by the magnet 7 Which is of such a character as to neutralizeother disturbin fields occasioned by the current flow throng iv tl-ieconductors embodied in the lamp, the disturbing magpet igfprceswhich.impair the arcs stability are substantial y eut a ed W i i s a y: dificult a atermine the magnetic fields which, disturb the ar man arelamp, 1, hayefq md, from extensive experiments, that a, device hayingthe form shown iirFigc 3 isvem efiiemii e in stabilizing thearc.Consequent y, it may be inferred that a magnet q character shown anddescribed an( having poles formed at 9 and ]0 (Fig.3) greatly minimizesthe magnetic disturbing forces inipres-sentripen thearc 1. I am; awarethat eec tromagnets hayingexciting windings connected to the supplycircnits ofarp lamps are old-in the art audit is well known that mas ta' h sl l e ta. rwi ad ise s: lampsto preclude ea a e uxesfronrcbs;turbingtl earcs, ti eievetpat l a n tl e to r0 oseima nets 0,1? tiecllar disclosed in sp et fication for stabiliz fiiig the. arcs ii arelamps.

W lule l have, shown and. described, one embodiment of? my inventien, itis evident that many modifications and, changes may be made withoutdeparting from} spirit hereo s {I d p msh, h fl s 9 limit sel totheprecis e disclosureherein set,

I Is s y ai m i -1. lwtse a masqmar sing a m st e i dasfia a ma lt a m eew n t 2 dis a a p an d a conductor]? n electr c curreiit dl'spesed p rMa aw m es i atal estroesa a ee e mbaac a at oad pt n nd; st

posed opposite to the are, said sleeve made of-' paramagnetic materialand pnoviiled with a longitudinal slot.

2. An electric arc lamp comprising elm-- trodes adaptedrto maintain anaxe between their. arcing ends, a conductor for electric currentdisposed adjacent to said electrodes. and an arc-stabilizing member ofparamagnetic material substantially surrounding said'conductor adjacentto the are.

3 Anelectricapq lamp comprising electrodes adapted to maintain an arebetween their arcing ends, a, conductor fpl' electric current disposedadjacent to said electrodes and,a helicalshapczl'sleeve embracing saidconductor and disposed opposite to the arc, said,slee\ e being made oiniagneiizahle n1aterial electric arc lamp comprising electrodes adaptedto maintainan arc between their, arcing ends a conductor for electriccurrent di sposed,aeljacent to said,electrodes. and,a sleeve embracingsaid conductor, said sleeve being made of paramagnetic materialaiidproyided witlra, longitudinal slot for fqrmmg a pairof magneticpoles when the sleeve; issubjected to a magnetizing force.

5, Anlelectric arc lamp comprisingelectrpdes adaptedto maintain a n agebetween their arcing ends, a conductor for electric curi-entdisposedadjacent to, said electrodes, an ,a sleeveembracing saidconductor and disposed opposite to the are, said sleeve being made, ofvparama netic material and provided with alongitudinal slot1bymeans o fwhich a pair of,manetic poles may be formedvon the SlQfiYe wfen the sameis subj ectepl .to a ,magnetizingforee,

n testimony Whereof I have hereunto subscribed my nameithis 5thdayofApril 1 JOHNt-LU DINSMOOR;

Witnesses;

9 HANSEN firm fi1 FStMilkaPPWQQQ QK Qseat a ymire a nsg mmissioner ofPatents,

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